It is good that you have made a wise choice so early on here. I am here new - day 45 for me, a mere 20 days before you joined.
I decided to join not for making money but to be able to have a voice and impact. I learned that this comes with a high enough SP, so, I invested in STEEM and Powered Up.
If you look at the the movers and shakers, they all have a high reputation score and a high SP. When your / my vote makes a significant impact, people pay attention to what you say.
So, think in those terms and keep growing your SP. Even if you started making significant rewards, keep it here and Power Up - do not withdraw and spend it.
All the best!